Dear all, until now a percect number of delegates have confirmed their attendance, namely 28 (see annex). Comment: A number is called perfect if the sum of its integer factors (excluding itself, of course) is equal to the number. 28 is one of the few perfect numbers since 28 = 1 + 2 + 4 + 7 + 14. Other perfect numbers are 6 and 496. There are not very many of them and I don't really know whether there is another one. However, it is unknown (as far as I know) whether the the total number of them is finite or infinite. There are still some answers missing (from Australia, France, India,... and a few others). A nonperfect number of attendees would be even better and maybe the largest attendance in TC6 history. Thus I wait for some positive answers. Best regards Otto